set_guides

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are supplied, so the description carries the full burden. It mentions that guides are visible to the user, but omits whether vertical/horizontal replace or append to existing guides, what happens to unspecified axes, what 'clear' resets, and whether the change is undoable or persisted with the document.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with no wasted words; the purpose and units appear immediately. It is lean to the point of under-specification, but nothing in it is redundant.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutation tool with four undocumented parameters, no annotations and no output schema, one sentence is not enough. An agent cannot infer replace-vs-append semantics or the role of 'clear'/'visible', which are exactly the details needed to call this correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% across four parameters, so the description must compensate. It only indirectly explains that the coordinate arrays are pixel positions; it says nothing about 'vertical' vs 'horizontal' arrays or the 'clear' and 'visible' flags, leaving half the argument surface unexplained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Set the document's guide lines') and even clarifies the unit ('pixel positions') plus concrete examples (thirds, layout grid). It is unambiguous and, since no sibling tool touches guides, no sibling differentiation is required.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The examples imply a use case, but there is no explicit when-to-use guidance, no prerequisites, and no statement about how this relates to other layout/canvas tools (e.g. resize_canvas, view_control) or when to prefer clearing guides instead of setting them.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.